Carbide forming and cluster build-up reactions in ruthenium carbonyl cluster chemistry

Article abstract of DOI:10.1016/0022-328X(90)85147-Q

The reinvestigation of an early synthesis of hexaruthenium carbido clusters has lead to the isolation of a number of new clusters which have been fully characterised by spectroscopic and crystallographic techniques.The thermolysis of Ru3(CO)12 in the presence of mesitylene (1,3,5-trimethylbenzene) at moderate temperatures yields two new clusters, 4-η²-CO)2(CO)13(η⁶-C6H3Me3)> (I) and 4-η²-CO)(CO)13(μ₂-η⁷-C6H3Me2CH2)> (II), the structures and reactivity of which indicate the origin and mechanism of formation of the carbido-carbon in thehexaruthenium carbido clusters 6-C6H3Me3)> (III) and (IV).A further product of the reaction is the decaruthenium carbido cluster dianion ^2- (V) which has the tetracapped octahedral geometry.The monohydrido-cluster anion ^- (VI) may be synthesised quantitatively from V by protonation.The nature of the hydrido-ligand in VI has been investigated in the solid state by NMR spectroscopy and it has been found to be fluxional, its location being temperature dependent.The decanuclear dianion V has been found to react with mercury salts to yield the 21 metal atom cluster dianion ^2- (VII) which consists of two tricapped octahedral nonaruthenium subclusters fused by a bi-facecapping (Hg3)²⁺ unit.